On the Behavior of Coupled Shear Walls: Numerical Assessment of Reinforced Concrete Coupling Beam Parameters

Modern construction of high-rise and tall buildings depends on coupled shear walls system to resist the lateral loads induced by wind and earthquake hazards. The lateral behavior of this system depends on the structural behavior of its components including coupling beams and shear walls. Although many research studies in the literature investigated coupling beams and shear walls, these studies stopped short of investigating the coupled shear walls as a system. Therefore, in this research, the effect of the coupling beam parameters on the nonlinear behavior of the coupled shear walls system was investigated. The full behavior of a 10-story coupled shear wall system was modeled using a series of finite element analyses. The analysis comprised of testing several coupling beam parameters to capture the effect of each parameter on system response including load-deflection behavior, coupling ratio, crack pattern, and failure mechanism. The results indicated that a span-to-depth ratio equal to two is a turning point for the coupling beam behavior. Specifically, the behavior is dominated by ordinary flexure for a ratio of more than two and deep beam behavior for a ratio of less than two. This study showed that the coupling beam width does not have a significant effect on the coupled shear wall response. Additionally, it was concluded that the excessive coupling beam diagonal reinforcement could significantly affect the coupled shear walls behavior and therefore an upper limit for the diagonal reinforcement was provided. Moreover, limitations on the longitudinal and diagonal reinforcement and stirrups are presented herein. The analysis results presented in this paper can provide guidance for practitioners in terms of making decisions about the coupling ratio of the coupled shear walls.&nbsp

Free flexural vibration analysis of one-way stiffened plates by the free interface modal synthesis method : discussion

Peer reviewed: YesNRC publication: Ye

Optimal configuration of active-control mechanisms

The relative merit of the different control configurations cannot be foreseen by considering only the controllability and observability conditions. A measure of the degree of controllability has to be defined to help choose the best control configuration. The optimal control configuration that maximizes the control effectiveness and minimizes the control cost is considered in this paper. The vibrational mode shapes, the structure-controller interaction, the control strategy, the control objective, and the control spillover are among the factors influencing the optimal placement of the control actions. The contribution of these factors in the control distribution problem is assessed through numerical examples. It is found that the structure-controller interaction, a factor usually neglected in previous studies, greatly affects the optimal control distribution. Quantitative measures of the degree of controllability are proposed. Finally the paper presents a methodology for dealing with the optimal control configuration problem, a problem that does not have a unique solution.On ne peut pas envisager le bien-fond\ue9 relatif des diff\ue9rentes configurations de contr\uf4le en ne consid\ue9rant que les seules conditions de contr\uf4labilit\ue9 et d?observabilit\ue9. Il est n\ue9cessaire de d\ue9finir une mesure du degr\ue9 de contr\uf4labilit\ue9 afin d?aider \ue0 choisir la meilleure configuration de commande possible. On examine dans ce document la configuration optimale qui maximalise l?efficacit\ue9 de la commande et r\ue9duit au minimum son co\ufbt. Les formes des modes vibrationnels, l?interaction structure-contr\uf4leur, la strat\ue9gie de commande, l?objectif de commande, de m\ueame que le d\ue9passement de capacit\ue9 de commande sont parmi les facteurs qui influent sur la mise en place optimale des actions de commande. La contribution de ces facteurs au probl\ue8me de la r\ue9partition de la commande est ici \ue9valu\ue9e au moyen d?exemples num\ue9rique. Nous avons d\ue9couvert que l?interaction structure-contr\uf4leur, facteur qui est habituellement n\ue9glig\ue9 par les \ue9tudes ant\ue9rieures, joue grandement sur la r\ue9partition de la commande optimale. Des mesures quantitatives du degr\ue9 de contr\uf4labilit\ue9 sont propos\ue9es. Enfin, le document pr\ue9sente une m\ue9thodologie permettant d?agir sur le probl\ue8me de la configuration de commande optimale, pour lequel existent plus d?une solution.Peer reviewed: YesNRC publication: Ye

Structural evaluation criteria based on past performance

Peer reviewed: YesNRC publication: Ye

Issues of control robustness in active structural control

Peer reviewed: YesNRC publication: Ye

Fiber-optics for evaluation of pavement reinforcement materials in resisting reflection cracking

Peer reviewed: NoNRC publication: Ye